Table 2.

Left atrial strain measured by different observers (mean ± SD, n = 64)

	Sct(%)	Scd(%)	Sr(%)
VSSLV
A1	−11.52 ± 2.69	−16.96 ± 7.28	28.49 ± 7.82
A2	− 11.14 ± 2.37*	−16.71 ± 7.10	27.85 ± 7.65*
B	− 11.12 ± 2.60#	−16.63 ± 7.24	27.75 ± 7.77
Mean	− 11.26 ± 2.46	− 16.77 ± 7.06	28.03 ± 7.58
P	0.004	0.244	0.007
VISLV
A1	−14.54 ± 3.72	−23.35 ± 10.63	37.89 ± 11.89
A2	−14.64 ± 3.67	−22.81 ± 9.95	37.46 ± 10.83
B	−15.14 ± 3.99	−24.21 ± 10.58	39.35 ± 11.58
Mean	− 14.77 ± 3.59	− 23.17 ± 10.33	38.23 ± 10.99
P	0.610	0.109	0.261
VISLA
A1	− 14.90 ± 4.13	− 23.72 ± 10.83	38.62 ± 12.19
A2	−14.72 ± 4.03	− 23.73 ± 10.57	38.45 ± 11.69
B	−14.77 ± 3.83	− 24.36 ± 10.95	39.13 ± 11.77
Mean	−14.80 ± 3.88	− 23.94 ± 10.49	38.73 ± 11.56
P	0.264	0.967	0.607

When using VSS_LV, there were significant differences in intra-observer measurement of Sct and Sr, and inter-observer measurement of Sct (p < 0.05). Comparing VIS_LV and VIS_LA, there were no significant differences in intra-observer or inter-observer measurements (p > 0.05)

A1: First measurement made by observer A

A2: Second measurement made by observer A 1 month later

B: First measurement made by observer B

^#Inter-observer comparison of VSS_LV, VIS_LV, and VIS_LA (p < 0.05)

^*Intra-observer comparison of VSS_LV, VIS_LV, and VIS_LA (p < 0.05)